A railway company measuring its network: track geometry (elevations, depressions) and the contact force between pantograph and overhead traction line, to reduce wear and optimise travelling speed. The system runs in dedicated test trains and in standard in-service trains, installed in the power car or in wagons and must come as a complete solution from one source.
Measurement values without an exact track position are maintenance guesswork. A geometry defect or excessive contact force that cannot be localised on the line cannot be planned for: the operator either over-maintains everywhere or accepts speed restrictions and unexpected wear. The team needed every analog sample stamped to its exact position on the track reliably, at line speed.
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Position-true synchronisation: analog values (geometry, contact force) must be acquired simultaneously with the encoder position. Software timing drifts; only a hardware trigger holds at speed.
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Railway environment: the customer required railway EMC compatibility (no disturbance of existing frequency uses).
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Dual deployment: the same system must work in test trains and standard trains, in the power car or in wagons.
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One source: encoder interface, analog acquisition, drivers and support from a single supplier, available for the long lifecycle of rail programmes.
An onboard PC (Windows) with two CompactPCI Serial cards. The CPCIs-1711 acquires the rotary encoders, 4 FPGA-based function modules, incremental / SSI / BiSS / EnDat 2.2 / Sin-Cos, RS422 up to 5 MHz (20 MHz on request), optical isolation 1000 V and fires a hardware trigger.
On that trigger, the CPCIs-3121 captures the analog sensor values, 16 SE / 8 differential inputs, 16-bit, up to 100 kHz, per-channel programmable ranges, DMA, optical isolation 500 V, simultaneously with the counter values. Every sample carries its exact track position. Drivers and samples for Linux and Windows are included; real-time (Xenomai / RTX) on request.
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Defects are localised, not just detected, geometry and contact-force anomalies are mapped to the metre on the line.
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Maintenance shifts from blanket inspection to targeted, planned intervention, wear is reduced, travelling speed optimised.
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Hardware-triggered acquisition removes software-timing drift, trustworthy correlation between position and measurement at line speed.
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One platform, one driver family, one supplier, Made in Germany, long-term availability for multi-year rail programmes.
By synchronising analog measurement to encoder position in hardware, the customer turned raw onboard measurements into a maintenance map of the line, the prerequisite for reducing wear and lifting speed restrictions with confidence.
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